Don't ya just hate it when you tear something apart, fearing the 
worst and it turns out to be something simple?  Actually, we SHOULD 
all be glad when this happens but...

The heater switch is wonky on this '87 of mine.  First thing on a
cold morning the fan is dead or maybe gives a few squeeks... I
thought of horrible things deep inside that big black box.  When the
van is warm, everything is fine.  Turns out the switch is bad, fan
motor is fine.  Found this out by wiggling the switch by accident. 
I haven't replaced mine yet... how much did yours cost, Gerry?

As for why it's getting the melties, well, based on the collective 
experience of 2 -you and me- I'd say the switch was either underbuilt 
for the load or made by Lucas. :)